Furnace



May 23, 1931 R. F. M0 NEAL FURNACE R. F. MCNEAL FURNACE Patented May 23, 1933 UNITED STATES i RAYMOND F. MCNEAL, OF CHICAGO, ILLINOIS I summer. 7

Application filed April 8, 1932. "Serial No. 603,977.

The present invention relates to furnaces and particularly to furnace constructions and has to do with the adaptation of a boiler for use with gun type fuel burners.

Experience has taught that when gun type fuel burners are installed in furnaces or fireboxes of boilers disintegration takes place because of the intense heat applied in such fireboxes and also the combusted fuel, im-

19 pelled by pressure, often burns the headers and tube ends, thus necessitating early shutdown for extensive and expensive repair.

The present invention is directed to the provision of means whereby such objections can be overcome and whereby gun type fuel burners can be safely and satisfactorily used with boilers without premature disintegration of the boiler fireboxes and withall increasing the efliciency of such boilers because of such means.

Generally speaking, the invention contemplates a burner applied in an extension furnace wherein the fuel is combusted, and

which extension furnace is surrounded by water circulating pipes for cooling such extension and preheating the water, The pipes are protected by refractory material such as bricks or blocks so constructed and arranged as to enable ready removal of any blocks requiring replacement and the ready installation of new blocks with minimum loss of time. The blocks are interlocked to prevent accidental displacement in service and may be set up without mortar or similar binding agents.

An object of the present inventionis to provide means whereby gun type fuel burners and other high temperature burners may 0 be used for boilers without-causing disintegration or other damage to the boiler structure.

Another object of the invention is to pro vide a furnace extension which extension is 45 watercooled and which is disposed in direct communication with the boiler firebox.

A further object of the invention'is to pro vide a furnace extension applicable to a boiler furnace or firebox for lengthening the path of travel of the combustible fuel to prevent excessive heat in the boiler firebox and thus eliminate damage to the furnace.

A still further object ofjthe invention is to provide an auxiliary cylindricalcombustion box having refractory lining and water 5.5 tubes in the lining for cooling the-same.

A yet further object of the inventionis to provide a furnace extension which is cylindrical and which has cooling pipes about its periphery and refractory interlocked blocks surrounding said pipes and defining the cylindricalcombustion chamber of said extension.

An important object of the inventio'nre sides in the provision of an extension furnace 55 which is generally cylindrical in shape and which is provided with embedded water flues which increase turbulence, afford higher furnace temperatures and generally achieve higher boiler elficiencywith a minimum of heat loss and without undueidisintegration of the boiler or extension furnace structure.

A still further object is toprovide aheat' zone for high or low ratings, wherein circulating water carries off-excessive heat and f5 prevents damage to the tiles or blocks em bedding the water circulating means.

Another and yet further object 'of-the invention is to provide novel interlocked bricks 8 or blocks for lining a cylindrical combustion chamber. i A

The above, other and further objects of the invention will be apparent from the following description, accompanying drawings and appended claims. j

The furnace extension herein illustrated and described isadaptable for oil, gas or powdered coal. -However, the extension furnace may be readily employed for other .kinds Q0 offuel. j; s e

, The accompanying drawings'illustrateembodiments of the present invention and the views' thereof are as follows: 7

Figure 1 is afragmental sectional view of a fire tube boiler showing applied to the firebox thereof" an extension furnace constructed according tofand embodying the principles of'the'present invention.

Figure 2 is avertical sectional View taken substantially in the plane of line IIII of Figure 1.

Figure 3 is a fragniental sectional view through a boiler of the Scotch type showing applied thereto an oil burner extension embodying principles of the present invention and wherein two headers are used with such extension and connected at different points to the water space of the boiler.

Figure 4 is a vertical sectional view taken substantially in the plane of line 'IVIV of Figure 3.

be observed that a fire tube boiler designated generally at A is carried 011 the usual masonry setting designated at B. The boiler A has a combustion chamber, firebox, or furnace G into which open the ends of fire tubes 1. Theends of the tubes 1 are headed in the 26 header 2 which is connected in the usual manner to the usual crown plate 3. The space within the boiler A is for water and is designated at D and includes, in the form illus trated in Figure 1, a rear water leg or water space 4 and a front water leg or water space'5.

' The furnace extension, as illustrated in Figure 4, designated generally at E and as there illustrated includes a front header 6 which isof usual form and made as a ring. The boiler A has an opening? to thefirebox C of the same, with the water leg 5 surrounding such opening. I

At intervals the header 6 has headed therein tubes 8 arranged in cylindrical form about the axis ofthe extension E with its tubes ex tending. rearwardly and headed into the Water leg.5 of the'boiler. The tubes extend axially of the extension, so that the extension' is substantially horizontally, disposed. The tubes are fashioned to form the outline of the: extension, that is, the cylindrical outline orshape. of thesame.

The outer o'r-front end of the extension E is'supported by feet 9 resting on concrete piers 10, while the ijnner end is supported on legs or feet 11 resting on concrete piers 12.

The axisof'the extension E extends in the same general direction as the length of the firebox C of the boiler A but the extension is illustrated as inclined slightly to the hori-v zontal. i

' The tubes 8 are surround-ed by and embeddedin refractory material which refractory material defines a cylindrical combustion chamber F within the extension E.

The refractory material in the present in stance is made .up in the form of bricks or blocks wedge-shaped in radial section and substantially rectangular in axial section as maybe observed from Figures 1 and 2. Certain of these blocks or bricks 13' are provided with recesses or notches 14 in similar sides thereof for-surrounding portions of the surfaces of the tubes 8 to afford refractorypro tection'for the portions'of the tubes towards the combustion chamber F. Interfitting 0r 7 interlocking blocks 15 shown, in Figure 2, to be substantially wedge-shaped in transverse section are interposed between every two of the blocks 13 as may be observed from Figure 2. If desired, a heat-insulating coating 16 may be applied about the outer ends of the several bricks or blocks. If desired, a metallic or other covering 17 may be applied about the insulation coating 16.

Against the front face of the header 6 are .,ring blocks 18 suitably applied and held in Referring first to Figures 1 and 2 it will position, which blocks are of refractory material.- These blocks rest on a centrally disposed ring 19 of refractory material which forms the entrance opening to the combustion chamber F of the extension E. The insulating coating 16 may be applied over the front blocks 18 if desired, as shown at 19 in Figure 1. i e

A casing 20 is suitably attached to the front end. of the extension E for receiving the oil burner set, designated generally at G. The oil burner set G, among other things, includes a discharge nozzle and an oil supply pipe 21 and a pipe 22 communicating with a suitable source of fluid under pressure, such, for instance, as steam, for applying pressure to the oil to force the same into the combustion chamber F of the extension E. The usual valve 23 is provided for regulating discharge of the steam into the combustion chamber F. Another valve 24 is provided in the steam lipe for further adjustment of the steam sup- 1 y I As before stated, the inner ends ofthe water tubes 8 communicate with the front water leg or water space 5 of the boiler A so that boiler water is circulated through these tubes and through the header 6, being delivered to the header 6 by pipes 25 leading from the water leg 4 and communicating with the header 6.- As the water becomes heated, which. it does in its cooling of the extension E, the heated water will rise and return to the boiler into the water legs 5, that is, from the inner ends of the extension.

It will be observed that the oil burner set G is of thegun fed type, thatis, of the type which discharges the oil with considerable force. The provision of the oil burner extension Eallows the combustion of this oil to take place in the combustion chamber F of the extension which extension iswatercooled,

with the combustion chamber walls of refractory' material, so that little, if any, damage is imparted to the extension because of the excessive heat present in the combustion zone of the oil burner. This combustible fuel, or combusted fuel as it then becomes, passes into the firebox C of the boiler where it passes through the fire tubes 1 to the stack, thus heating the water in the boiler and evaporating it. The circulation of. the boiler water through the extension E preheats this water T Lil its

, ble by removing the key bricksand then the recessed bricks 13. New bricks may be installed by hooking the recesses or notches 14 of the bricks 13 about the tube8 and then inserting the necessary key bricks 15 to firmly interlock all of the bricks together.

Referringto the forms illustrated in Figures 3 and 4, it will be observed that the arrangement is substantially the same as described with reference to Figures 1 and 2 ex cept that the extension here designated E is slanted upwardly away from the front of the furnace 8 of the boiler K, the boiler illustrated in Figures 3 and 4 being of the Scotch type.

The boiler K of Figures3-and 4 has an upper water space 26 and a lower water space 27, with the firebox or combustion chamber 8 defined by corrugated walls 28. The firebox H has a front opening 29 surrounded by masonry or cement 30.

The oil burner extension E has a front header 31 and a rear header 32 which headers are connected at intervals by axially extending water tubes 33. The tubes 33 are arranged in a single series in cylindrical form parallel to the axis of the extension E.

The header 31 is connected by pipes 34 with the water space 26 of the boiler, while the header 32 is connected by connections 37 to the water space 27 of the boiler. Water,

- therefore, circulates from the boiler, that is,

from the space 27 through the header 32, thence through the tubes 33 to the front header 31, thence returns to the water space 26 through the pipe 34, such circulation of boiler water cooling the extension E, at the same time taking up some heat as to become preheated to a certain degree, thus hastening vaporization of the water within the boiler K.

The combustion chamber of the extension E is designated at L and is cylindrical in shape. The cylindrical combustion chamber L is defined by refractory blocks or bricks 38 and 39 similar, respectively, to the blocks 13 and 15 of the extension E. The blocks 38 are provided with notches 40 for engaging the tubes 33 to protect the same from the combustion chamber L.

The bricks 38 and 39 may, if desired, be covered by an insulating coating'41 spread about the exterior of'the same which, in turn,

may be surrounded by a covering 42.

The extension E is supported on front legs 43 rising from piers 44 in the foundation and rear legs 45 rising from piers v46 of the foundation;

The front face of'the front header 31 covered by refractory slabs or blocks 47 sup porting in place a central refractory ring 48 forming an entrance 49 to the combustion chamber L of the extension. The blocks 47 are shown as covered by insulating material 50 which in turn is covered by'a cover 51. An oil burner casing 52 is supported on the cover 51 with the oil burner set E arranged to discharge through the opening 49 to the combustion chamber L of the extension E;

The gun type fuel burner G delivers the fuel under pressure into the combustion chamber L where it is ignited and creates a zone of maximum heat. The combusted fuel passes into the firebox H of the boiler K for heating the water there contained.

- Inasmuch as the zone of maximum heat is within the refractory oil burner extension E, no damage results to the combustion chamber H of the boiler K, even though the gun type of oil burnerfbe utilized in connection with such boiler.

' The bricks 39 and 38 of the extension E are placed in the same manner as described with reference to the vbricks13 and 15 of the extension E' of Figures land 2.

It will be observed that this invention provides: an oil burner extension forapplication to boilers wherein the gun type of oil burners may be utilized withoutdamaging the fireboxiof the boilers to anyextent whatsoever. The zone of maximum heat is within'-tl1e".combustion"chamber of the extension the walls of whichare of refractory material and watercooled, thus prolonging the life of such walls to a marked degree. The refractory wall structures of these extensionsis such as to enable ready repair and replacement should any of the refractory material have to be replaced through wear duev to long service'or through accidental breakage.

It will be. observed thatby the use of an oil burner extension .of the character herein .desc'r1be d,,the-combusted fuel under pressure is spent to some extent before the same entersthe fireboxes of the boilers, thus relieving the fireboxes of the boilers from'the intense heat generated in the zone of ignition ofthefueh' V Thecirculationof the boiler waterthrough the extension has the double purpose of cool- .ing the extensionand of preheating the boiler water, thus not only efliciently cooling the refractory walls of the combustion chamber of" the extension but preheating the boiler water to an extent whereby vaporization thereof within the boiler is accelerated, thus increasing the efficiency? of the boiler and re'- ducing the costiof fuel, 7

The circular arrangement of the furnace eliminates pockets and also eliminates losses of the influx of unconsumed combustible products, such as occur in square or semicircular furnaces. v It also furnishes complete circulation of the products of combustion. .Furthermore, heat transferrance to the refractories is equally divided and in turn the heat from the refractories is reflected equally to the combustible matter, a

The invention is not limitedto oil burners because it is illustrated and described in connection therewith, asit is equally-adaptable to other fuels, such as gas powdered coal, coke and the like, and also to Stoker-fed boilers. r

The water ring or header is an important par-tof the presentinvention in that it aids watercirculation, thus enhancingthe efliciency of the cooling of the extension and prolonging its life. I

' term."brick-" has beenused herein generically, and not by way of limitation and is intended 'to includeany refractory material suitable for such use, made in the form of blocks, tiles or bricks. I

The invention has-been described herein more or less precisely as to details, vyet it is f to be'understood that the invefntionis not to invention. I

"be limited thereby aschanges'may be made in the arrangement and" proportion 'of parts and equivalents'may be substituted without departing from the spirit-and scope of the with'ia boiler having a firebox, a furnace extensioncommunicatingwith said firebox and bricks; embedding said .tubesand completelysur'rounding' every one of said-tubes and defining the combustion chamber of said extension, and: afuelburner arranged for fuel discharge into said extension through'the outer end thereof, said tubes-being connected tothe water spaces of said'boiler for circulating boiler water through said tubes and header to. cool said extension.

4:. A boiler havingja firebox, a furnace extension opening into'said firebox, saidextension having. a cylindrical wallof refractory bricks, water tubes extending i through said wall axially ofsaid extensi-on', headers at each end of said extension in communication with said tubes, and connections between said headersand different partsofthe water-space of" the boiler for i, circulating boiler ,water through said headers 1 and tubes: for: cooling said extension, all-of said tubes being completely surrounded by the material of said wallwith no-fpart of vany tube directly expos'ed to the interior. of said chamber.

" Intestimonywhereof I havehereunto subscribed my name at Chicago, Cook County,

Illinois.-"1 v.

I 1 r F; MONEAL.

spaces ofsaid boiler for circulatingboiler fwater through saidliningto cool the same;

2. Inv combustion with a boiler havin a firebox, a cylindrical combustion chamber communicating with said firebox, a plurality 4 of axially extending'water tubes disposed all around said combustionfchambe'r, refractory material embedding all of said tubes and defining said cylindrical combustion chamber,

every one of said tubes being completely surrounded by saidlining, a header-atone end of said chamber into which said tubes open,

-and means connecting said header and the other ends of said tubes withthe water compartlments of the boiler for circulating boiler water through the tubes of said combustion chamber to cool'said chamber circulating-water. i I

and heat the i 3. In a'boil'er arrangement, incombination 

